Existing solutions for lightweight camshafts have been attempted or contemplated in the past. German patent no. DE 102 60 115 B4 discloses a camshaft and method for producing the same, in which a tubular main body is produced from a carbon fiber composite material, into which tubular main body a plurality of metal sleeves for receiving cam elements are introduced. During the production of the main body, a corresponding number of metal sleeves are positioned at predefined points along the main body and laminated into the carbon fiber composite material.
In this manner, a lightweight camshaft may be produced, which lightweight camshaft comprises a tubular main body made from a carbon fiber composite material, metal sleeves connected to the main body, and cams seated on the metal sleeves. The metal sleeves are laminated into the carbon fiber composite material of the main body and serve a retaining function. The disadvantage of the camshaft and method disclosed in the German patent no. DE10260115 B4 is that the operational transmission forces between the metal sleeves that receive the cam elements and the carbon fiber composite material of the tubular main body can be high. High forces at the connection between the metal sleeves and the composite fiber material, which forces can often push the limits of the joint strength, result in the connection not having permanent strength, which strength is dependent, in particular, on the mechanical and thermal loading of the camshaft. The metal sleeves have a central passage, through which the inner part of the main body extends, the main body not forming a sufficient bedding module, depending on the use conditions of the camshaft, in order to produce a permanently loadable seat for the metal sleeves if the loading of the camshaft exceeds defined values.
A further disadvantage of the camshaft as disclosed in DE10260115 B4 is the fact that the main body is formed by a complicated winding process that requires the metal sleeves to be positioned onto the main body by way of a complicated method, in order to subsequently continue and complete the winding process. The accuracy with which the metal sleeves have to be positioned on the main body during the winding process has to be very high, since the position of the metal sleeves defines the later position of the cams.